Surgical gowns, surgical drapes, surgical face masks, surgical scrubs, and sterile wrap and sterilization peel pouches (hereinafter collectively “surgical articles”), in order to function satisfactorily, must achieve a balance of properties, features and performance characteristics. Such surgical articles have, as a principal matter, been designed to greatly reduce, if not prevent, the transmission through the surgical article of biological liquids and/or airborne contaminates. In surgical procedure environments, such liquid sources include the gown wearer's perspiration, body fluids from the patient, such as blood, and life support liquids such as plasma and saline. Examples of airborne contaminates include, without limitation, biological contaminants, such as bacteria, viruses and fungal spores. Such contaminates may also include particulate material such as, without limitation, lint, mineral fines, dust, skin squames and respiratory droplets. A measure of the barrier fabric's ability to prevent the passage of such airborne materials is sometimes expressed in term of filtration efficiency.
Such surgical articles further should be comfortable during use, that is, while being worn. The breathability of the surgical article, that is, its rate of water vapor transmission, is an important measure of how comfortable a surgical article is to use. Other characteristics of surgical articles that impact upon the comfort of the article during use include, without limitation, the drapeability, cloth-like feel and hand and cool, dry feel of the articles.
Surgical articles also require a minimum level of strength and durability in order to provide the necessary level of safety to the user of the article, particularly during surgical procedures.
Finally, surgical articles desirably are inexpensive to manufacture, utilizing lightweight materials that enhance the comfort of the wearer during use, but also reduce the cost of such articles.
The use of liquid impervious, breathable multi-layer barrier fabrics of various constructions is known. Surgical articles formed from liquid repellent fabrics, such as fabrics formed from nonwoven webs or layers, have provided acceptable levels of liquid imperviousness, breathability, cloth-like drapeability, strength and durability, and cost. However, the need exists nonetheless for improved, cloth-like, liquid impervious, breathable barrier materials for use in forming surgical articles, as well as other garment and over-garment applications, such as personal protective equipment applications (i.e., workwear, for example), in which some or all of the above performance characteristics and features are desirable or necessary. Other personal protective equipment applications include, without limitation, laboratory applications, clean room applications, such as semiconductor manufacturing, agriculture applications, mining applications, environmental applications, and the like.
Various low surface tension liquids are used in hospitals and other sites where surgical and medical procedures are performed. Low surface tension liquids, such as isopropyl alcohol, can combine with blood and other fluids to create wettable pathways capable of carrying viruses through various surgical articles mentioned above. For instance, surgical articles formed using microporous thermoplastic polyolefin-based films and film/nonwoven laminates are inherently hydrophobic, and resist the passage of blood and other aqueous fluids which might carry viruses. However, these films and laminates are typically less resistant to the passage of low surface tension liquids. Thus, when blood or other aqueous fluid is combined with isopropyl alcohol or another low surface tension liquid, a vehicle can be formed for carrying blood-borne viruses and the like through the surgical articles.
With the foregoing in mind, there is a need or desire for improved breathable thermoplastic films and film/nonwoven laminates that prevent the passage of low surface tension liquids, such as isopropyl alcohol, as well as aqueous-based liquids.